Health-relatedness and Long-term Objectives: Atherosclerotic renal artery stenosis is a common problem for which there is no clear consensus on diagnosis or therapy. There likely exists a progression wherein renal ischemia leads to neuroendocdne activation, hypertension, and renal insufficiency potentially resulting in acceleration of therosclerosis, further renal dysfunction, myocardial infarction, stroke and death. The current proposal tests whether revascularization of a stenotic renal artery plus optimum medical therapy is associated with improved clinical outcomes when compared with optimum medical therapy alone. Specific Aims, Design and Methods: Cardiovascular Outcomes in Renal Atherosclerotic Lesions (CORAL) is a randomized clinical trial that will contrast the effect of optimum medical therapy alone to stenting with optimum medical therapy, on a composite cardiovascular and renal endpoint: cardiovascular or renal death, myocardial infarction, hospitalization for congestive heart failure, stroke, doubling of serum creatinine level, and need for renal replacement therapy. This endpoint will be adjudicated by a clinical events committee masked to treatment assignment. The secondary endpoints 1) evaluate the mechanisms linked to clinical events; 2) describe differential effectiveness in critical end-organs; 3) determine the value of stenting from the patient and the health policy perspectives, measured as quality of life and cost effectiveness; and 4) evaluate for clinically relevant differences in treatment effectiveness within the primary endpoint. The primary entry criteria are an atherosclerotic renal stenosis equal to or >60% with a 20 mmHg systolic pressure gradient and systolic hypertension equal to or >155 mmHg on 2 or more anti-hypertensive medications. A slight predominance of women is expected, and high priority will be placed on minority recruitment. Approximately 2200 patients will undergo a baseline evaluation with randomization occurring in 1080. The study has 90% power to detect a 28% reduction in primary endpoint hazard rate. Thisproposal describes the role of the Angiography CoreLab (University of Virginia CoreLab and Over read Services, UVA CORS) in the CORAL trial.